Bean拷貝工具類性能比較
引言
幾年前做過一個項目，接入新的api接口。為了和api實現解耦，決定將api返回的實體類在本地也建一個。這樣做有兩個好處
- 可以在api變更字段的時候保持應用穩定性
- 可以對返回的實體的屬性做處理，以提高可讀性。例如接口返回long類型的時間戳，則將該字段在本地實體類中對應字段設置為date類型方便使用。
大致是這樣的一個應用場景。當時剛畢業，充斥的都是A.setName(B.getName)這種類型的代碼。當字段非常多的時候看起來非常臃腫，最重要的給人感覺不優雅。
再給我一次機會
如果上天再給我一次機會，我會跟他說，我有四種工具類可以優雅的解決這個問題。
分別是
- org.apache.commons.beanutils.PropertyUtils.copyProperties
- org.apache.commons.beanutils.BeanUtils.copyProperties
- org.springframework.beans.BeanUtils.copyProperties
- net.sf.cglib.beans.BeanCopier
Talk is cheap, show me code
定義SourceBean
package com.zhaoyangwoo.model;
/**
* Created by john on 16/7/28.
*/
public class SourceBean {
private Integer age;
private String title;
private String source;
private Boolean eat;
public SourceBean(Integer i, String name, Boolean eat, String source) {
this.age = i;
this.title = name;
this.eat = eat;
this.source = source;
}
public void setAge(Integer age) {
this.age = age;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public Boolean getEat() {
return eat;
}
public void setEat(Boolean eat) {
this.eat = eat;
}
public String getSource() {
return source;
}
public void setSource(String source) {
this.source = source;
}
public Integer getAge() {
return age;
}
}
定義DesBean
package com.zhaoyangwoo.model;
/**
* Created by john on 16/7/28.
*/
public class DstBean {
private Integer age;
private String title;
private Boolean eat;
private String self;
public String getSelf() {
return self;
}
public void setSelf(String self) {
this.self = self;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public Boolean getEat() {
return eat;
}
public void setEat(Boolean eat) {
this.eat = eat;
}
}
測試函數
package com.zhaoyangwoo.biz;
import com.zhaoyangwoo.model.DstBean;
import com.zhaoyangwoo.model.SourceBean;
import net.sf.cglib.beans.BeanCopier;
/**
* Created by john on 16/7/28.
*/
public class BeanCopyMain {
private static BeanCopier beanCopier = BeanCopier.create(SourceBean.class, DstBean.class, false);
public static void main(String[] args) throws Exception {
Integer[] times = {10000, 1000, 10};
for (int i = 0; i < times.length; i++) {
Integer time = times[i];
doCopy(time, (x, y) -> org.apache.commons.beanutils.PropertyUtils.copyProperties(y, x), "org.apache.commons.beanutils.PropertyUtils.copyProperties");
doCopy(time, (x, y) -> org.apache.commons.beanutils.BeanUtils.copyProperties(y, x), "org.apache.commons.beanutils.BeanUtils.copyProperties");
doCopy(time, (x, y) -> org.springframework.beans.BeanUtils.copyProperties(y, x), "org.springframework.beans.BeanUtils.copyProperties");
doCopy(time, (x, y) -> beanCopier.copy(x, y, null), "net.sf.cglib.beans.BeanCopier.copy");
doCopy(time, (x, y) -> {
y.setEat(x.getEat());
y.setTitle(x.getTitle());
y.setAge(x.getAge());
}, "getter/setter");
}
}
static void doCopy(Integer time, BeanCopy beanCopy, String type) throws Exception {
long startTime = System.currentTimeMillis();
for (int j = 0; j < time; j++) {
SourceBean sourceBean = new SourceBean(j, "source" + j, false, "abc");
DstBean dstBean = new DstBean();
beanCopy.copy(sourceBean, dstBean);
}
System.out.printf("執行%d次用時%dms---------%s%n", time, System.currentTimeMillis() - startTime, type);
}
interface BeanCopy {
void copy(SourceBean from, DstBean to) throws Exception;
}
}
執行結果如下
結論
根據上面的運行結果，我們可以得出以下結論
- property少，寫起來也不麻煩，就直接用傳統的getter/setter，性能最好
- property多，轉換不頻繁，那就省點事吧，使用org.apache.commons.beanutils.BeanUtils.copyProperties
- property多，轉換很頻繁，為性能考慮，使用net.sf.cglib.beans.BeanCopier.BeanCopier，性能近乎getter/setter。但是BeanCopier的創建時消耗較大，所以不要頻繁創建該實體，最好的處理方式是靜態化或者緩存起來。